This is a single band filter constructed by means of a straight tube or conduit with branch lines consisting of a volume and a tube connected in parallel and with the main conduit, but with an alteration at will of the opening into the main conduit. The narrowness of the single band can be modified by the modifications in the size of this hole without seriously affecting its other characteristics. The performance of the single band filter reported upon is in accord with theory mentioned.
Proceedings of the Iowa Academy of Science
©1922 Iowa Academy of Science, Inc.
Stewart, G. W.
"A Variable Single Band Acoustic Filter,"
Proceedings of the Iowa Academy of Science, 29(1), 150-150.
Available at: https://scholarworks.uni.edu/pias/vol29/iss1/34